1. Field of the Invention
The present invention concerns a loop type antenna with disymmetrical feeding.
2. Description of the Prior Art
The characteristics of loop antennas are known, in particular their wide passband and their relatively open radiation pattern which causes them to be used especially in reception.
In most cases the loop is used alone, i.e.; without any associated reflector, and it is fed either by a two-wire line, the two conductors of which go up to the two ends of the loop (which is not closed on itself), or by a coaxial line, the loop being connected to the line by the interposition of a symmetrizer device.
Currently used loop antennas are ill-suited for use in transmission because of their SWR (standing wave ratio) which is disadvantageous for the energy radiated.
Furthermore, if the output of the transmitter, as is usually the case, is done on a coaxial line, the use of the symmetrizer further increases the SWR. In addition, this approach enables suitable operation only in a relatively narrow frequency range (around the matching frequency of the symmetrizer), and this is incompatible with wide band transmission.